Southwire 500-ft 12 -AWG Red Solid Copper THHN wire ( By-the-roll )

The Second Hot Conductor for 240V Circuits Southwire 12 AWG Red THHN: The Phase B Hot Conductor for 240V Branch Circuits in Conduit The Southwire 12 AWG red THHN 500 ft solid copper wire is the conductor color electricians reach for when wiring 240V branch circuits in conduit. Per NEC convention, the red conductor serves as the second hot leg (Phase B) of any 240V single-phase circuit, paired with a black conductor (Phase A hot), a white conductor (neutral), and a green conductor (ground) to complete the four-wire pull. Electric ranges, dryers, water heaters, air conditioning condensers, EV chargers, hot tubs in conduit, well pumps in conduit, and any 240V residential equipment installed via conduit-protected wiring all rely on the red THHN as the second hot conductor. �� Free Nationwide Freight �� NEC Phase B Color Standard ���� Trusted Southwire Brand ✅ UL Listed THHN/THWN-2 On this page Southwire 12 AWG red THHN key highlights Why red specifically: NEC color convention for Phase B Red black white green: the complete 240V conductor set Common 240V applications using red THHN Electric ranges, dryers, and water heaters EV charger circuits Air conditioning condenser circuits THHN in conduit vs UF-B direct burial for outdoor 240V What THHN is and how it differs from NM-B Conduit fill calculations for THHN Temperature rating and wet location use Southwire 12 AWG red THHN specifications Why IB Lighting Southwire 12 AWG red THHN FAQs Who this wire is built for Red THHN vs yellow THHN: when each color is right Installation best practices The Southwire 12 AWG red THHN 500 ft solid copper wire is the standard NEC-conforming second hot conductor for residential and commercial 240V branch circuits installed in electrical conduit. As a 12 AWG red THHN wire, this product delivers the 20-amp circuit capacity required for typical 240V residential applications (electric dryers at 240V/30A use larger gauge wire, but many smaller 240V loads operate at 240V/20A using 12 AWG conductors). As red THHN 500 ft by the roll, the standard 500-foot spool length matches typical electrician inventory for active 240V circuit work, with one roll typically serving multiple 240V circuit installations across active projects. As 240V circuit wire red, the conductor color specifically identifies this wire as a Phase B hot conductor per NEC color conventions, distinguishing it visually from the Phase A hot (black), neutral (white), and equipment ground (green) conductors that complete the 240V circuit pull. As red hot conductor THHN, the Southwire 12 AWG red THHN uses the standard THHN/THWN-2 dual insulation specification (PVC primary insulation under a clear nylon outer jacket), suitable for installation in conduit, raceway, and other approved THHN applications in both dry and wet locations. Every Southwire 12 AWG red THHN 500 ft roll ships nationwide from IB Lighting with free freight. Manufacturer specifications are available at the official Southwire website. Southwire 12 AWG red THHN solid copper wire, the standard second hot conductor for 240V circuits in conduit. Southwire 12 AWG Red THHN Key Highlights Color NEC Phase B Red Saturated red insulation is the NEC-standard color for the second hot conductor of 240V single-phase circuits and for Phase B in commercial three-phase systems. Gauge 12 AWG Solid Copper 12 AWG solid copper conductor rated for 20-amp branch circuits. The right specification for typical 240V/20A residential loads. Type THHN / THWN-2 Dual Rated Dual-rated insulation: PVC primary under clear nylon outer jacket. Suitable for dry locations (THHN) and wet locations (THWN-2). Length 500 Foot Roll Standard electrician inventory roll size. One roll typically serves multiple 240V circuit installations across active project work. Installation Conduit Pull Standard Designed for installation in electrical conduit, raceway, panels, and approved THHN applications. NOT for direct burial without conduit. Temperature 90C Rated 90C insulation rating handles high-temperature applications. Ampacity per 75C tables for typical residential/commercial use per NEC. Voltage 600V Rated 600-volt insulation rating handles residential 120V/240V applications and commercial 277V/480V three-phase systems. Listed UL Listed UL Listed and manufactured to applicable NEC requirements for THHN/THWN-2 building wire. Inspector-ready for permitted installations. Why Red Specifically: NEC Color Convention for Phase B The Southwire 12 AWG red THHN is red for a specific reason rooted in NEC electrical color convention. Understanding the convention helps clarify why electricians purchase red THHN specifically rather than substituting another color for the second hot conductor of a 240V circuit. NEC conductor color conventions: Black: Hot leg 1 (Phase A in single-phase residential service, Phase A in three-phase commercial systems). The primary hot conductor. Red: Hot leg 2 (Phase B in single-phase residential 240V service, Phase B in three-phase commercial systems). The second hot conductor for 240V circuits. Blue: Hot leg 3 (Phase C in three-phase commercial systems only). Not typically used in residential applications. White: Neutral conductor (per NEC must be white or gray). Carries return current from loads to the panel. Green or bare: Equipment grounding conductor (per NEC must be green, green with yellow stripe, or bare copper). For a 240V single-phase residential circuit (which is the standard configuration for electric ranges, dryers, water heaters, AC condensers, and similar 240V residential equipment), the cable must contain TWO hot conductors that connect to opposite phases of the split-phase service. The 240V potential exists between the two hot legs. Per NEC color convention, the two hots are black (Phase A) and red (Phase B). Mixing or substituting colors creates ambiguity that complicates future troubleshooting, maintenance, and inspection. For three-phase commercial systems, the color convention extends to include blue for the third hot leg. The Southwire 12 AWG red THHN handles both single-phase residential 240V applications (where red is the second hot) and three-phase commercial applications (where red is Phase B). The conductor performs identically; only the role differs based on the system configuration. For 120V circuits (which use only one hot conductor), red THHN is not typically used. The single hot conductor on a 120V circuit is conventionally black. Using red on a 120V-only circuit can create confusion during inspection or future troubleshooting, even though the cable would function correctly. Red Black White Green: The Complete 240V Conductor Set For a typical 240V residential branch circuit installed in conduit, the electrician pulls four separate THHN conductors through the conduit. The Southwire 12 AWG red THHN is one of these four conductors. Understanding the complete conductor set helps clarify how to plan and source the materials for a 240V circuit installation. The standard 240V circuit conductor set for residential applications: One black THHN: Phase A hot conductor. Connects to one bus bar of the panel. One red THHN (this product): Phase B hot conductor. Connects to the opposite bus bar of the panel. The 240V potential exists between this conductor and the black conductor. One white THHN: Neutral conductor. Required for circuits with any 120V loads (such as range/dryer accessories that require 120V); some 240V-only circuits omit the neutral. One green THHN (or bare copper): Equipment grounding conductor. Connects to the panel equipment ground bar. For a typical 12 AWG 240V circuit (handling 20-amp loads), one 500-foot roll each of red, black, white, and green THHN provides enough material for multiple complete circuits depending on the run lengths. Electricians stocking inventory for active 240V circuit work typically maintain rolls of all four colors in inventory. For some specialized installations, additional colors may be used: blue for three-phase Phase C in commercial work, yellow as an alternative identification color for specific applications, brown/orange for special voltage systems. The standard residential 240V circuit, however, uses the red/black/white/green four-conductor configuration. When sizing the conduit for the pull, the total conductor count (4 conductors for a typical 240V circuit) and the conductor gauge (12 AWG for this product) determine the minimum conduit trade size per NEC Chapter 9 conduit fill tables. A 4-conductor 12 AWG pull typically requires at least 1/2-inch EMT or PVC conduit, with 3/4-inch conduit recommended for easier pulling and future conductor additions. Common 240V Applications Using the Southwire 12 AWG Red THHN The Southwire 12 AWG red THHN serves residential and commercial 240V branch circuits where the 20-amp circuit capacity matches the load requirements. Understanding the common applications helps confirm the 12 AWG specification is correct for your specific project. Common residential 240V/20A circuits using the Southwire 12 AWG red THHN: Air conditioning condenser circuits: Many residential central AC condensers operate at 240V with 15-20 amp running current and higher starting current. Most residential condensers fit within 20-amp circuit capacity. Smaller water heaters: Some smaller-capacity residential electric water heaters (specifically 20-gallon and smaller “point of use” units) operate at 240V/20A. Larger water heaters require 240V/30A and use 10 AWG conductors instead. Workshop equipment: Smaller workshop equipment (small welders, smaller compressors, smaller dust collectors) operating at 240V with under 20-amp current draw. Smaller window AC units: Some larger window air conditioners specifically rated for 240V operation rather than standard 120V. Garage door openers (heavy duty): Industrial-grade garage door operators for oversized doors sometimes operate at 240V. Specific 240V receptacle circuits: Dedicated 240V/20A receptacles for specific equipment that the homeowner anticipates installing. Commercial three-phase 277V circuits: In commercial buildings using three-phase 277V/480V systems, 12 AWG conductors handle 20-amp branch circuits including LED lighting installations at 277V. For higher-current 240V applications (electric ranges at 40-50A, electric dryers at 30A, larger water heaters at 30A, EV chargers at 30-50A, hot tubs at 30-50A), larger gauge red THHN is required. The 12 AWG specification serves the 20-amp applications specifically; step up to 10 AWG red THHN for 30-amp circuits, 8 AWG red THHN for 40-amp circuits, and so on. Electric Ranges, Dryers, and Water Heaters While the Southwire 12 AWG red THHN handles 20-amp 240V circuits, the most common residential 240V equipment (electric ranges, dryers, large water heaters) typically requires larger gauge conductors. Understanding the gauge requirements for different equipment helps confirm the right red THHN specification for your specific installation. Standard residential 240V equipment circuit requirements: Electric range (typical): 240V/40A or 240V/50A circuit. Requires 8 AWG red THHN (40A) or 6 AWG red THHN (50A). The 12 AWG red THHN is NOT correct for most electric ranges. Electric dryer (typical): 240V/30A circuit. Requires 10 AWG red THHN. The 12 AWG red THHN is undersized for most electric dryers. Electric water heater (40 to 80 gallon, typical): 240V/30A circuit. Requires 10 AWG red THHN. The 12 AWG red THHN is undersized for most full-size electric water heaters. Electric water heater (under 20 gallon, point-of-use): 240V/20A circuit. The 12 AWG red THHN may be the right specification for these smaller units. Verify the specific water heater’s circuit requirement before specifying. Range hood (electric): Most range hoods operate at 120V/15A; some larger commercial-style residential hoods operate at 240V/15-20A and may use 12 AWG conductors. The practical takeaway: verify the specific equipment’s circuit ampacity requirement before sourcing the conductor gauge. For most full-size residential 240V appliances, the 12 AWG red THHN is undersized. The 12 AWG specification specifically matches 240V/20A applications including some HVAC equipment, smaller equipment, and certain commercial installations. For the larger 240V circuits typical in residential applications (electric range, dryer, water heater, EV charger), browse our broader IB Lighting electrical wire collection for the appropriate gauges of red THHN and corresponding companion conductors. EV Charger Circuits Level 2 EV chargers operate at 240V and typically require 30-amp to 50-amp circuits depending on the charger’s continuous current rating. The Southwire 12 AWG red THHN is appropriate for the smaller end of EV charging installations but is typically undersized for full-speed Level 2 charging. EV charger circuit requirements by charging current: 16A continuous charging (40A breaker per NEC 80% rule): 240V/16A actual draw. Requires 10 AWG red THHN at minimum. The 12 AWG red THHN is undersized. 24A continuous charging (30A breaker): Lower-amperage Level 2 charging. Requires 10 AWG red THHN. The 12 AWG is undersized. 32A continuous charging (40A breaker): Mid-tier Level 2 charging. Requires 8 AWG red THHN at minimum. 48A continuous charging (60A breaker): Full-speed Level 2 charging. Requires 6 AWG red THHN. 80A continuous charging (100A breaker, rare): Highest-tier home charging, typically requires dedicated EV-specific service equipment. For typical Level 2 EV charger installations, the conductor pull through conduit includes red, black, white (if the charger requires neutral, which most do not), and green THHN at the appropriate gauge for the charger’s circuit ampacity. The Tesla Universal Wall Connector specifically includes adjustable amperage settings that allow the installer to configure the unit for the available circuit capacity, which can match the conductor gauge selected for the installation. For homeowners specifically planning to install a 16-amp Level 2 EV charger (sometimes used for lower-cost installations or where the existing electrical service cannot support higher amperage), the Southwire 12 AWG red THHN may be marginally adequate, but 10 AWG red THHN provides better voltage drop performance and code-compliant ampacity headroom. For all serious EV charging installations, 10 AWG or larger red THHN is the right specification. Air Conditioning Condenser Circuits Air conditioning condenser circuits are one of the most common applications where the Southwire 12 AWG red THHN is genuinely the right specification. Most residential AC condensers operate at 240V with current draws that fit within 20-amp circuit capacity, making 12 AWG conductors the appropriate gauge. Typical AC condenser circuit requirements: 1.5 to 2.5 ton condensers: Typically 240V/15A or 240V/20A circuits. The Southwire 12 AWG red THHN handles these comfortably. 3.0 to 3.5 ton condensers: Typically 240V/20A to 240V/25A circuits. The 12 AWG handles up to 20A; for 25A circuits, step up to 10 AWG. 4.0 to 5.0 ton condensers: Typically 240V/30A or larger circuits. Requires 10 AWG red THHN at minimum. The AC condenser circuit conductor pull typically includes only red, black, and green THHN (no neutral, because the AC condenser is a 240V-only load with no 120V accessory loads). This is a three-conductor pull rather than the four-conductor pull required for circuits with 120V loads. For each AC condenser installation, verify the equipment’s specific MCA (Minimum Circuit Ampacity) and MOCP (Maximum Overcurrent Protection) ratings on the equipment nameplate. The MCA determines the minimum conductor ampacity required; the MOCP determines the maximum breaker size allowed. The 12 AWG red THHN is appropriate for installations where the MCA falls within the 20-amp ampacity rating of 12 AWG conductors. THHN in Conduit vs UF-B Direct Burial for Outdoor 240V Circuits For outdoor 240V circuits, electrical contractors have two NEC-compliant approaches: pulling THHN conductors (including the red THHN for the second hot) through PVC or rigid metal conduit, or running direct-buried UF-B cable without conduit. Understanding the trade-off helps clarify when each approach is preferred. Choose THHN-in-conduit (using the Southwire 12 AWG red THHN as one of the four conductors) when: the installation specifically requires conduit per local code or design specification, future cable changes are anticipated (the conduit provides ongoing accessibility for swapping conductors), the run crosses through areas subject to physical damage (driveways outside protected zones, exposed areas), or commercial design standards favor conduit-protected wiring. Choose UF-B direct burial (such as the Southwire 10/3 UF-B) when: the installation is residential landscape or yard electrical work where conduit would be unnecessary labor, direct burial significantly reduces the trenching depth and labor compared to conduit installation, the run will not require future cable changes, or budget considerations favor the lower-labor direct-burial approach. For residential outdoor 240V applications specifically (hot tubs, well pumps, pool equipment, detached subpanels), both approaches are common. UF-B direct burial tends to be more popular for residential work because of the labor savings; THHN-in-conduit is more common in commercial work and in residential installations where the designer/contractor specifically prefers conduit. Both are equally code-compliant for their appropriate use cases. For the conduit approach, the typical 240V/20A circuit conductor set is one black THHN, one red THHN (this product), one white THHN (if neutral is needed), and one green THHN at the appropriate gauge. The Southwire 12 AWG red THHN serves the 20-amp portion of this conductor set; larger gauge red THHN serves higher-current circuits. What THHN Is and How It Differs from NM-B THHN stands for Thermoplastic High Heat-resistant Nylon-coated, and it represents a fundamentally different building wire type from the NM-B (Romex) cable that most residential branch circuits use. Understanding the difference clarifies why THHN is the right choice for conduit installations. THHN is a single-conductor building wire designed to be installed inside conduit, raceway, or other enclosed protective system. Each THHN conductor is a discrete wire with primary PVC insulation under a thin clear nylon outer jacket. Multiple THHN conductors of different colors are pulled through the same conduit to create complete circuits. THHN cannot be installed directly in framing without conduit protection per NEC. NM-B (Romex) cable is a multi-conductor assembly with all the required conductors (hot, neutral, ground) bundled inside a single outer jacket. NM-B can be installed directly in framing without conduit per NEC Article 334. The single-jacket construction simplifies residential installation but cannot match the flexibility and protection of THHN-in-conduit installations. Practical differences in use: THHN advantages: Color-coded conductors allow flexible circuit configurations, conduit provides protection against physical damage, future conductor additions or changes are accessible, suitable for commercial and industrial applications, wet location rated (THWN-2 dual rating). THHN disadvantages: Conduit installation requires additional labor, conduit material adds cost, more complex to plan for residential rough-in. NM-B advantages: Single-pull installation, no conduit required, lower material cost for residential branch circuits, simpler to plan for residential rough-in. NM-B disadvantages: Indoor dry locations only, no protection against physical damage in exposed areas, future cable changes require accessing the existing run. The Southwire 12 AWG red THHN is the conduit-installation choice for residential and commercial 240V/20A circuits. For framed-wall installations without conduit, NM-B cable (in various gauges and configurations) is the typical residential choice. Conduit Fill Calculations for THHN Pulling the Southwire 12 AWG red THHN through conduit requires verifying that the conduit is large enough to accommodate the conductor count without exceeding NEC conduit fill limits. Understanding the conduit fill rules helps plan the installation correctly. NEC Chapter 9, Table 1 establishes maximum conduit fill percentages: 1 conductor: Maximum 53% fill of conduit cross-sectional area. 2 conductors: Maximum 31% fill. 3 or more conductors: Maximum 40% fill. For a typical 240V circuit pull of 4 conductors (red, black, white, green) at 12 AWG, the conduit fill calculation determines the minimum conduit trade size. Per NEC Chapter 9 Table 4 (conductor and conduit specifications), the typical answer is: 1/2-inch EMT conduit: Handles 4 conductors of 12 AWG THHN at code-compliant fill. This is the typical minimum for residential 240V/20A installations. 3/4-inch EMT conduit: Provides additional fill capacity, easier pulling, and room for future conductor additions. Generally preferred for installations where future expansion is anticipated. 1-inch EMT conduit: Provides significant additional capacity. Used for longer runs, multiple parallel circuits in the same conduit, or installations specifically designed for future expansion. For specific installations, refer to current NEC tables or use NEC-approved conduit fill calculators to verify the conduit size matches the specific conductor count and gauges. Most installations use 1/2-inch or 3/4-inch conduit for typical residential 240V circuit pulls. Temperature Rating and Wet Location Use The Southwire 12 AWG red THHN carries a 90C temperature rating, which is one of the higher temperature ratings for residential and commercial building wire. The dual THHN/THWN-2 rating provides additional installation flexibility for wet-location applications. Temperature rating considerations: 90C insulation rating: The maximum continuous operating temperature for the conductor insulation without degradation. Higher than the 60C or 75C ratings of older building wires. Practical ampacity: Per NEC, the ampacity rating for terminations typically uses the lower of the conductor rating, the termination rating, or 75C tables. For typical residential installations, the 75C tables govern the practical current capacity even though the conductor itself is rated for 90C operation. High-temperature application benefit: The 90C rating provides headroom for applications where the conductor may experience elevated temperatures from environmental conditions, multiple conductors in conduit, or adjacent heat sources. The THWN-2 wet location rating allows the Southwire 12 AWG red THHN to be installed in: Wet locations: Conduit installations subject to water exposure (outdoor conduit, conduit through damp basements, conduit in wet processes). Underground conduit: THHN/THWN-2 conductors pulled through PVC or rigid metal conduit installed underground. Outdoor exposed conduit: THHN/THWN-2 in conduit installed outdoors above ground. The wet location rating distinguishes THHN/THWN-2 from standard THHN-only conductors (which are rated only for dry locations). The Southwire 12 AWG red THHN dual rating provides genuine installation flexibility for projects that may include both dry and wet location segments. Southwire 12 AWG Red THHN Specifications Southwire 12 AWG Red THHN Specifications Product Type THHN/THWN-2 Building Wire (Single Conductor) Brand Southwire Gauge 12 AWG Conductor Material Solid Copper Conductor Type Solid (single conductor strand) Insulation PVC Primary with Clear Nylon Outer Jacket Insulation Color Red (NEC Phase B color) Length 500 ft Roll Voltage Rating 600V Temperature Rating 90C Circuit Capacity 20-Amp Branch Circuits Location Rating Dry and Wet Locations (THHN/THWN-2 dual rated) Installation Inside Conduit, Raceway, or Equivalent Protective System Common Application Phase B Hot Conductor of 240V Single-Phase or Three-Phase Commercial Circuits Code Compliance NEC Article 310 (Conductors for General Wiring) Certification UL Listed Master Electrician Led Why Buy the Southwire 12 AWG Red THHN from IB Lighting IB Lighting is a family-owned, nationwide reseller of electrical supplies, led by licensed Master Electrician Imad Boussi. 240V circuit installations require coordinated material sourcing across multiple conductor colors, conduit sizing, and supporting hardware, and that Master Electrician expertise matters when contractors need to verify gauge sizing for specific equipment, plan complete conductor sets for new circuit installations, or specify the right conduit fill for multi-conductor pulls. Every Southwire 12 AWG red THHN 500 ft roll ships with free nationwide freight. Browse our complete electrical wire and cable collection for the broader range including companion Southwire 12 AWG yellow THHN for related applications, consider Southwire 10/3 UF-B as the direct-burial alternative for outdoor 240V circuits, pair with a Tesla Universal Wall Connector for EV charging projects, or explore other Southwire products. Southwire 12 AWG Red THHN FAQs Why is THHN wire color-coded? THHN conductor colors follow NEC convention for circuit identification: black is Phase A hot, red is Phase B hot (for 240V single-phase or three-phase circuits), blue is Phase C hot (three-phase only), white is neutral, and green or bare copper is equipment ground. The color coding makes circuit identification immediate during installation, troubleshooting, and inspection. The Southwire 12 AWG red THHN serves specifically as the second hot conductor on 240V circuits, paired with a black THHN for the first hot. What 240V applications use 12 AWG red THHN specifically? The Southwire 12 AWG red THHN is appropriately sized for 240V/20A applications including: air conditioning condensers in the 1.5 to 3.0 ton range, smaller workshop equipment (small welders, small compressors), some larger window AC units, dedicated 240V receptacles for specific equipment, smaller point-of-use water heaters, and commercial three-phase 277V/20A LED lighting circuits. For higher-current 240V applications like electric ranges (40-50A), dryers (30A), full-size water heaters (30A), and EV chargers (32-48A), larger gauge red THHN is required. Can I use 12 AWG red THHN for an electric dryer circuit? No. Standard residential electric dryers require 240V/30A circuits, which need 10 AWG red THHN at minimum. The Southwire 12 AWG red THHN is undersized for typical dryer circuits and would create a fire safety hazard if used. Verify your dryer’s nameplate ampacity rating, then select the appropriate red THHN gauge: 10 AWG for 30A, 8 AWG for 40A, 6 AWG for 50A circuits. How many 12 AWG red THHN conductors fit in 1/2-inch conduit? Per NEC Chapter 9 conduit fill tables, 1/2-inch EMT conduit accommodates approximately 9 conductors of 12 AWG THHN at the maximum 40% fill for 3 conductors. For a typical 240V circuit requiring 4 conductors (red, black, white, green), 1/2-inch EMT provides comfortable fill capacity with room to spare. For installations anticipating future conductor additions or for easier pulling, 3/4-inch EMT provides additional capacity. Verify specific conduit sizing using current NEC tables for your specific conductor count and gauge. What is the difference between THHN and THWN-2? Both designations refer to the same physical wire. THHN means Thermoplastic High Heat-resistant Nylon-coated, rated for dry locations. THWN-2 means Thermoplastic Heat- and Water-resistant Nylon-coated, rated for both dry and wet locations at 90C. Most modern THHN conductors carry the dual THHN/THWN-2 rating, which allows installation in either dry or wet conditions. The Southwire 12 AWG red THHN carries this dual rating, providing genuine installation flexibility. Can I install 12 AWG red THHN without conduit? No. THHN/THWN-2 single conductors must be installed inside conduit, raceway, or other approved protective system per NEC Article 310. The conductor cannot be installed directly in framing without conduit protection. For installation directly in framed walls without conduit, NM-B (Romex) cable is the correct cable type. THHN-in-conduit and NM-B installations serve different purposes and are not interchangeable. Can the Southwire 12 AWG red THHN be used outdoors? Yes, when installed in approved outdoor conduit. The THHN/THWN-2 dual rating allows the conductor to be installed in PVC conduit, rigid metal conduit, or other approved outdoor raceway systems including underground conduit. The conduit provides the physical protection against weather and physical damage; the THWN-2 rating allows the conductor to operate in the wet conditions inside outdoor conduit. For direct-buried installations without conduit, UF-B cable is the appropriate alternative. Why is red used for the second hot conductor? NEC convention assigns red as the standard color for the second hot conductor of 240V single-phase circuits and as Phase B in three-phase commercial systems. The color convention provides immediate visual identification of conductor function during installation, troubleshooting, and inspection. Other colors (black for Phase A, blue for Phase C, white for neutral, green for ground) complete the standard color coding system that all NEC-compliant electrical installations follow. How long is the Southwire 12 AWG red THHN roll? The Southwire 12 AWG red THHN ships in 500-foot rolls (by-the-roll quantity). This length matches typical electrician inventory for active 240V circuit installation work, with one roll typically serving multiple 240V circuit installations across active project work. For larger projects requiring 1000 feet, multiple rolls may be needed or larger spool quantities may be appropriate. What other red THHN gauges are available? Red THHN is available in essentially all common building wire gauges to match the various 240V circuit ampacities: 14 AWG (15A circuits), 12 AWG (this product, 20A), 10 AWG (30A circuits like dryers and water heaters), 8 AWG (40A circuits like smaller ranges and EV chargers), 6 AWG (50A circuits like larger ranges and 48A EV chargers), and larger gauges for higher-current applications. Match the gauge to the specific equipment’s circuit ampacity requirement. Should I buy red and black THHN together? For 240V circuit installations, yes. Most 240V circuits require both a red conductor (Phase B hot) and a black conductor (Phase A hot) of the same gauge as part of the complete conductor pull. Electricians typically maintain rolls of red, black, white, and green THHN at the gauges they commonly install. Stocking individual color rolls separately allows flexible mixing for specific circuit configurations rather than relying on pre-bundled multi-color packages. How long does shipping take from IB Lighting? Most Southwire 12 AWG red THHN 500 ft orders leave the warehouse within 1 to 2 business days and arrive at your address within 5 to 6 business days depending on destination. Every shipment travels with free freight. Tracking is provided as soon as the order is picked up by the carrier. Who the Southwire 12 AWG Red THHN Is Built For The Southwire 12 AWG red THHN serves three primary buyer types in residential and commercial electrical work. The first is electrical contractors handling 240V circuit installations in conduit, which represents a meaningful portion of residential remodel work, commercial new construction, and HVAC equipment circuit work. For these contractors, the red THHN is the second hot conductor of every 240V circuit they install in conduit, paired with a black THHN of the same gauge and supporting white and green companion conductors. The second buyer is the HVAC installer running air conditioning condenser circuits and similar 240V mechanical equipment circuits. For these installers, the Southwire 12 AWG red THHN is appropriately sized for the typical 240V/20A AC condenser circuit, and the 500-foot roll matches the consumption pattern across multiple HVAC equipment installations. The third buyer is the commercial electrical contractor handling three-phase 277V LED lighting installations, commercial 240V/20A circuits, and other commercial 12 AWG applications. For these contractors, the Phase B red conductor is part of every three-phase commercial circuit, and the 500-foot roll provides standard contractor inventory. For higher-current applications (full-size residential 240V appliances, EV charger circuits at 30A , larger commercial circuits), larger gauge red THHN is the right specification. Browse the broader IB Lighting electrical wire collection for the complete range of red THHN gauges. Red THHN vs Yellow THHN: When Each Color Is Right For electricians considering which THHN colors to stock, the distinction between the Southwire 12 AWG red THHN and the Southwire 12 AWG yellow THHN reflects the different roles these colors serve in electrical installations. Choose the Southwire 12 AWG red THHN (this product) when: installing 240V single-phase circuits (where red is the standard second hot conductor), wiring three-phase commercial systems (where red is Phase B), the application specifically calls for red conductor identification per the design specification, or stocking general inventory for 240V circuit work. Choose the Southwire 12 AWG yellow THHN when: the application calls for an alternative identification color beyond the standard red/black/blue convention, marking specific circuits for tracing purposes, special voltage system identification, or installations where local code or design preference calls for yellow conductors. For most residential and commercial work, red THHN is the more frequently consumed color because of its role as the standard second hot conductor on 240V circuits. Yellow THHN serves more specialized identification roles in specific applications. Electricians stocking general inventory typically maintain larger quantities of red, black, white, and green THHN, with yellow stocked in smaller quantities for the specific applications that require it. Installation Best Practices for the Southwire 12 AWG Red THHN Installing the Southwire 12 AWG red THHN follows standard practices for THHN conductor pulls through conduit. Most installation issues are preventable with proper planning at the conduit sizing, conductor pulling, and termination stages. Plan the conductor set: For a typical 240V circuit pull, identify all required conductors before pulling: red (Phase B hot), black (Phase A hot), white (neutral, if 120V loads are included), and green (equipment ground). Have all conductors on hand and labeled before starting the pull. Verify conduit fill: Confirm the conduit is large enough for the planned conductor count per NEC Chapter 9 tables. For a 4-conductor 12 AWG THHN pull, 1/2-inch EMT typically suffices; 3/4-inch EMT provides easier pulling and future expansion capacity. Lubricate the pull: Use wire-pulling lubricant compatible with THHN insulation for longer or more difficult pulls. The lubricant reduces friction and prevents jacket damage during the pull. Pull conductors together: Pull all conductors of the circuit simultaneously rather than one at a time. This ensures all conductors travel through the conduit together and prevents the difficulty of pulling individual conductors into already-occupied conduit. Maintain identification at terminations: Strip the conductor ends and terminate each color to the appropriate device or breaker terminal. Red goes to the second hot leg of the 240V breaker; black goes to the first hot leg; white goes to the neutral bar; green goes to the ground bar. Maintain conductor identification throughout the installation. Verify polarity and grounding: Test the installed circuit for correct polarity (red to Phase B, black to Phase A, white to neutral, green to ground) and proper grounding continuity before energizing. Use a multimeter or circuit analyzer to verify the connections before equipment is connected. Label and document: Label the breaker at the panel and any junction boxes along the run for future identification. Note the conductor gauge, circuit purpose, and applicable code references on permit documentation if the installation is permitted. Browse the complete IB Lighting electrical wire and cable collection, compare with the companion Southwire 12 AWG yellow THHN for specialized identification applications, consider Southwire 10/3 UF-B for direct-burial alternative to outdoor 240V conduit installations, pair with a Tesla Universal Wall Connector for EV charging circuit installations, explore other Southwire products, or visit our customer FAQ hub. Manufacturer technical sheets are available at the official Southwire website. Ready to Order Southwire 12 AWG Red THHN? 240V circuit installation, HVAC equipment wiring, or commercial three-phase project? Talk to a Master Electrician-led team that knows the conductor color conventions and gauge sizing for 240V applications. Call (800) 674-9019